CopyOnWriteArrayList iterator() method in Java Last Updated : 11 Jul, 2025 Comments Improve Suggest changes Like Article Like Report The iterator() method of CopyOnWriteArrayList returns an iterator over the elements in this list in proper sequence. The iterator does NOT support the remove method. Syntax: public Iterator iterator() Parameters: The function does not accept any parameters. Return Value: The function returns an iterator over the elements in the list. Below programs illustrate the above function: Program 1: Java // Java Program to illustrate the CopyOnWriteArrayList // iterator() method in Java import java.util.concurrent.CopyOnWriteArrayList; import java.util.*; public class GFG { public static void main(String[] args) { // create object of CopyOnWriteArrayList CopyOnWriteArrayList<Integer> ArrLis = new CopyOnWriteArrayList<Integer>(); // Add elements ArrLis.add(32); ArrLis.add(67); ArrLis.add(67); ArrLis.add(100); // print CopyOnWriteArrayList System.out.println("CopyOnWriteArrayList: " + ArrLis); // Call iterator() method of Iterator iteratorVals = ArrLis.iterator(); // Print elements of iterator // created from CopyOnWriteArrayList System.out.println("The iterator values" + " of CopyOnWriteArrayList are:"); // prints the elements using an iterator while (iteratorVals.hasNext()) { System.out.println(iteratorVals.next()); } } } Output: CopyOnWriteArrayList: [32, 67, 67, 100] The iterator values of CopyOnWriteArrayList are: 32 67 67 100 Program 2: Java // Java Program to illustrate the CopyOnWriteArrayList // iterator() method in Java import java.util.concurrent.CopyOnWriteArrayList; import java.util.*; public class GFG { public static void main(String[] args) { // create object of CopyOnWriteArrayList CopyOnWriteArrayList<String> ArrLis = new CopyOnWriteArrayList<String>(); // Add elements ArrLis.add("gopal"); ArrLis.add("gfg"); ArrLis.add("jgec"); ArrLis.add("sudo"); // print CopyOnWriteArrayList System.out.println("CopyOnWriteArrayList: " + ArrLis); // Call iterator() method of Iterator iteratorVals = ArrLis.iterator(); // Print elements of iterator // created from CopyOnWriteArrayList System.out.println("The iterator values" + " of CopyOnWriteArrayList are:"); // prints the elements using an iterator while (iteratorVals.hasNext()) { System.out.println(iteratorVals.next()); } } } Output: CopyOnWriteArrayList: [gopal, gfg, jgec, sudo] The iterator values of CopyOnWriteArrayList are: gopal gfg jgec sudo Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CopyOnWriteArrayList.html#iterator-- Comment More infoAdvertise with us Next Article CopyOnWriteArraySet iterator() method in Java G gopaldave Follow Improve Article Tags : Misc Java Java-Collections Java - util package Java-Functions Java-CopyOnWriteArrayList +2 More Practice Tags : JavaJava-CollectionsMisc Similar Reads CopyOnWriteArraySet iterator() method in Java The iterator() method of CopyOnWriteArraySet returns an iterator over the elements in this Set in proper sequence. The iterator does NOT support the remove method. Syntax: public Iterator iterator() Return Value: The function returns an iterator over the elements in the Set. Below programs illustrat 2 min read CopyOnWriteArraySet iterator() method in Java The iterator() method of CopyOnWriteArraySet returns an iterator over the elements in this Set in proper sequence. The iterator does NOT support the remove method. Syntax: public Iterator iterator() Return Value: The function returns an iterator over the elements in the Set. Below programs illustrat 2 min read CopyOnWriteArraySet iterator() method in Java The iterator() method of CopyOnWriteArraySet returns an iterator over the elements in this Set in proper sequence. The iterator does NOT support the remove method. Syntax: public Iterator iterator() Return Value: The function returns an iterator over the elements in the Set. Below programs illustrat 2 min read CopyOnWriteArrayList indexOf() method in Java The indexOf(Object o) method of CopyOnWriteArrayList returns the first occurrence of the element passed in the list. It returns -1 if the element is not present in the list. Syntax: public int indexOf(Object o) Parameters: The function accepts a parameter o whose first occurrence is to be returned. 3 min read CopyOnWriteArrayList indexOf() method in Java The indexOf(Object o) method of CopyOnWriteArrayList returns the first occurrence of the element passed in the list. It returns -1 if the element is not present in the list. Syntax: public int indexOf(Object o) Parameters: The function accepts a parameter o whose first occurrence is to be returned. 3 min read CopyOnWriteArrayList indexOf() method in Java The indexOf(Object o) method of CopyOnWriteArrayList returns the first occurrence of the element passed in the list. It returns -1 if the element is not present in the list. Syntax: public int indexOf(Object o) Parameters: The function accepts a parameter o whose first occurrence is to be returned. 3 min read Like